SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99c78e0cde0f41a385d7d83c017169da9b6db9e79e35771c470b1a36d0a821c3' 
  AND token = 'fi6o2F8Yc36+jmTUDphy9ERY+pHzLPBEZhBTMliYvMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}